/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.dubbo.config.spring.status;

import org.apache.dubbo.common.extension.Activate;
import org.apache.dubbo.common.logger.Logger;
import org.apache.dubbo.common.logger.LoggerFactory;
import org.apache.dubbo.common.status.Status;
import org.apache.dubbo.common.status.StatusChecker;
import org.apache.dubbo.common.utils.CollectionUtils;
import org.apache.dubbo.config.spring.extension.SpringExtensionFactory;

import org.springframework.context.ApplicationContext;

import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.ResultSet;
import java.util.Map;

/**
 * DataSourceStatusChecker
 */
@Activate
public class DataSourceStatusChecker implements StatusChecker {

  private static final Logger logger = LoggerFactory.getLogger(DataSourceStatusChecker.class);

  @Override
  @SuppressWarnings("unchecked")
  public Status check() {
    ApplicationContext context = null;
    for (ApplicationContext c : SpringExtensionFactory.getContexts()) {
      if (c != null) {
        context = c;
        break;
      }
    }

    if (context == null) {
      return new Status(Status.Level.UNKNOWN);
    }

    Map<String, DataSource> dataSources = context.getBeansOfType(DataSource.class, false, false);
    if (CollectionUtils.isEmptyMap(dataSources)) {
      return new Status(Status.Level.UNKNOWN);
    }
    Status.Level level = Status.Level.OK;
    StringBuilder buf = new StringBuilder();
    for (Map.Entry<String, DataSource> entry : dataSources.entrySet()) {
      DataSource dataSource = entry.getValue();
      if (buf.length() > 0) {
        buf.append(", ");
      }
      buf.append(entry.getKey());

      try (Connection connection = dataSource.getConnection()) {
        DatabaseMetaData metaData = connection.getMetaData();
        try (ResultSet resultSet = metaData.getTypeInfo()) {
          if (!resultSet.next()) {
            level = Status.Level.ERROR;
          }
        }
        buf.append(metaData.getURL());
        buf.append("(");
        buf.append(metaData.getDatabaseProductName());
        buf.append("-");
        buf.append(metaData.getDatabaseProductVersion());
        buf.append(")");
      } catch (Throwable e) {
        logger.warn(e.getMessage(), e);
        return new Status(level, e.getMessage());
      }
    }
    return new Status(level, buf.toString());
  }

}
